What is the target temp for the battery if the car is plugged in?

[Dave EV]

Phoenix is hot and it looks like my battery is running pretty hot at 107 degrees. Yikes. Is there any way to cool it? For now, I have the charging set to charge on plug in.

Ouch, that is hot for just sitting there.

Reading above it looks like the trick to cool the pack is to charge in range mode at a very low current.

I would be curious as to what happens if you just turn the car on? What temperature does the TMS target then?

 

[shrink]

Ouch, that is hot for just sitting there.

Reading above it looks like the trick to cool the pack is to charge in range mode at a very low current.

I would be curious as to what happens if you just turn the car on? What temperature does the TMS target then?

drees, good to see you from over at MNL. Looks like that worked. I just range charged at 30 amps for about 45 minutes. Battery got down to 95 F. I'll turn the amperage down when I get home:

 

[rgjones]

You can go down to 13A in range mode to get cooling cycles and minimal energy use while giving more time before range mode charges the battery more than you might wish.
Note, you must be on a 200V+ circuit - unfortunately cooling does not occur on 110V (unless the battery is >40C)
The car cooling alg also takes into account the ambient air sensor, which sadly easily reads higher than true ambient, often slowing the cooling.
Is there any way to keep the heat from building up in your garage?
I can vent my garage door a few inches and open a side door which helps somewhat, but then the temp outside my garage is usually cooler than inside, something you might not have in AZ!
The garage my be cooler in the early morning, allowing you to pre-cool your battery before you take off for the day.

 

[yobigd20]

 

[driver_EV]

Had idea to check my battery temp in the evening after driving in the hot afternoon, realized it was 40C = 104F, and wishing it were cooler, I decided to try opening the trunk lid, and pointing a small fan across the top of the ESS/PEM to help cool it down. Anyone else tried this, think it is a good idea in hot weather?

 

[wiztecy]

Had idea to check my battery temp in the evening after driving in the hot afternoon, realized it was 40C = 104F, and wishing it were cooler, I decided to try opening the trunk lid, and pointing a small fan across the top of the ESS/PEM to help cool it down. Anyone else tried this, think it is a good idea in hot weather?

That little fan won't make any difference in bringing down the temp of the battery, the mass is too large plus the coolant is at 104F. The correct and only way to bring the ESS temps down is to plug the Roadster in and begin charging at 240@12 to 20 AMPs to activate the HVAC. Since you're at 40C you may be able to get the 110V mobile charger to work the HVAC, I believe it'll start the HVAC system when battery / ESS is greater or equal to 37C. Not sure if 15AMPS will work, 20 will.

 

[jaanton]

The 110v at 15A can cool the ESS/battery. A couple weekends ago I gave some demo "spirited" drives which got the ESS quite warm and after those I just plugged in the 110v at 15A and after just a couple minutes the car was aggressively cooling the pack. Interestingly, the mileage reading showed a reduction during cooling so I'm sure the car was using more than the 110v @15A (1650W) to cool the battery.
I've also just had my Roadster plugged in to 110v @ 15A for several hours and stopped by to check on it and the car was running all the cooling systems with the main front fan running putting out a good deal of heat. So don't ignore what just a 110v connection can do. Maybe the car decides it's got power, it should use it.

 

[driver_EV]

By morning the ESS was cooler to the touch, and the info display showed only 2 bars for batt temp instead of 4, so opening the trunk and blowing air across the top of the ESS does bring the temp down off that high reading. The day before I checked in the morning and it still felt warm when I opened the trunk. (my garage stays pretty warm this time of year) I was mainly wondering if I was the only one trying it, and if there is a concern about having the battery sitting for hours(or days) at 104F. I understand the cooling system operates when plugging in and charging the car, but this scenario does not involve charging on that day.

 

[djp]

Not much of the ESS is exposed under the trunk lid, you might cool the PEM slightly by opening the trunk but it won't make a difference to the battery.

Heat is the enemy of Li-Ion cells, especially the combination of sitting at high temperature and high state of charge for long periods of time. I run a cool down cycle whenever my battery temp is over 30C before packing it in for the night.

 

[wiztecy]

I agree with djp. Cool-down is essential in preserving a pack's life. If I'm greater than 28C I initiate my cool-down, especially after my commute back home or returning back from a trip. Can't wait for the UI to come in OVMS for that feature. I read cell degradation is exponential after 26C so I'm very receptive of the ESS temps. If its a hot day and there's a cool down opportunity to bring my 36C pack down to 28-30C I'll take it. The only two screens on my VDS are the Ideal miles and temp screen. That way I can switch back and fourth easily and monitor the entire car's system's health temperature wise speaking. The other screen is fun stuff I've never used nor cared about so I deselected it in settings.

Best recommendation is to park in the shade. I noticed a dramatic temp difference when I parked out in the open sun vs. parking in a covered multilevel public concrete parking garage. The pack has no chance to recover in the sun and just bakes.... plus the car radiates heat that was absorbed from the sun, so its a losing battle there. I was going to try covering my Roadster with the light grey cover to at least shield and reflect back some of the rays... but the parking garage which was a 5000 feet away was a better solution.

Opening the trunk and your little fan will however help the PEM. The PEM has heat sinks, and wisking away any temps from the cover (since heat rises) will help those electronics out that to me operate in very high temps for electronic components.

 

[driver_EV]

Thanks, I tried the cool-down by running a short charge cycle and noted the ESS temp cooled down pretty quickly.

 

[n2mb_racing]

Old thread, but seemed to be the most relevant.

I have a roadster 2.0 sport. I'm stuck parking in the sun at work and the temperature is rising to over 100 degrees now. It does seem like the cooling kicks on to limit the battery temperature to 104F (40C), even if the car isn't plugged in.

I have access to 110, so I tried plugging in and running a cooldown cycle using OVMS to see if that would help. It doesn't seem to. The car seems to be very slowly charging, but still holding the battery at 104F.

So, what's the best practice if you have to park in the sun in summer heat? Plug in or not? Park in the shade?

Or does it all not matter, since the thermal management is good.

 

[djp]

So, what's the best practice if you have to park in the sun in summer heat? Plug in or not? Park in the shade?

Definitely park in the shade if you can, and try to plug in if you're in the sun. The cool-down cycle won't work unless you're on a 240V circuit, but at least the 120V will supply enough power to run the fans rather than drawing from the battery. Keeping the SOC low will also prevent damage from the heat.

 

[n2mb_racing]

Yeah, I'll have to start coming in earlier to snag coveted spots underground...

SOC is at 81% since I charge in standard mode and have a short commute.

Does the car use the wall power to run things when available? I think it might only use the wall power when charging, then go back to running on battery until it tops off the battery 24 hours later...

 

[strider]

Old thread, but seemed to be the most relevant.

I have a roadster 2.0 sport. I'm stuck parking in the sun at work and the temperature is rising to over 100 degrees now. It does seem like the cooling kicks on to limit the battery temperature to 104F (40C), even if the car isn't plugged in.

I have access to 110, so I tried plugging in and running a cooldown cycle using OVMS to see if that would help. It doesn't seem to. The car seems to be very slowly charging, but still holding the battery at 104F.

So, what's the best practice if you have to park in the sun in summer heat? Plug in or not? Park in the shade?

Or does it all not matter, since the thermal management is good.

110 doesn't provide enough power to run the A/C. I believe Tesla made the assumption that since the act of charging at 110 won't heat up the batteries such that it would need the A/C (unlike higher charge rates) that A/C wasn't necessary from that source. As you say the car will use battery power to cool above 40C (104F). So if your only option is 110 plugging in won't make a difference. Park in the shade and run a cool down cycle when you get home.

I'm also trying to figure out the car's logic as to when it cools the battery while driving. Sometimes when I drive home w/ the A/C on in the cabin the battery is only at 20C or so when I get home. But other days it's at 35C. So something is causing the car to use the A/C to cool the batteries while driving but I can't figure out the pattern. I always drive in Performance mode.

- - - Updated - - -

Does the car use the wall power to run things when available? I think it might only use the wall power when charging, then go back to running on battery until it tops off the battery 24 hours later...

You're right, only when charging. The "shore power" concept is new to Model S.

 

[n2mb_racing]

More data...

I parked in a covered parking garage spot today. It's ~100F outside. The car reports 99F ambient and the battery is 99F as well.
When I parked in the sun yesterday, the car reported up to 130F ambient, and the battery went up to 104-106F maximum.

So, actually the active cooling does its job and probably doesn't make much difference in terms of battery stress or lifetime if you park in the sun or in the shade. Of course, parking in the sun will wear down the battery faster, since it is kicking on the A/C, but other than that, I can't see too much difference.

 

[strider]

More data...

I parked in a covered parking garage spot today. It's ~100F outside. The car reports 99F ambient and the battery is 99F as well.
When I parked in the sun yesterday, the car reported up to 130F ambient, and the battery went up to 104-106F maximum.

So, actually the active cooling does its job and probably doesn't make much difference in terms of battery stress or lifetime if you park in the sun or in the shade. Of course, parking in the sun will wear down the battery faster, since it is kicking on the A/C, but other than that, I can't see too much difference.

What did it report for PEM temperature? That is actually the component that I most worry about for long term health as heat is the enemy of solid state devices too. It's a pretty commonly replaced part although I have 47k miles on my original one.

 

[n2mb_racing]

What did it report for PEM temperature? That is actually the component that I most worry about for long term health as heat is the enemy of solid state devices too. It's a pretty commonly replaced part although I have 47k miles on my original one.

Good point. I didn't check on that. I believe it was similar to ambient, but I imagine the fans were running a lot more.

 

[n2mb_racing]

Another update. Today I did a standard mode charge at work at 109V 12A, without using cooldown, and it seems to be doing a good job of cooling the battery. Not as hot today, but the car reports ambient is 90F and the battery is 79F. Google says it is 87 outside, and I parked in the shade.

Interesting. I thought the car didn't cool the batteries on 110V.